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Motherboard replacement capacitor?? Answered

I have an Asus M3A79-T Deluxe motherboard I recovered, and one of the capacitors looks to be ripped out of place. Does anyone know where I can buy or find the correct replacement capacitor? I have identified which capacitor it is I just am lost on as to where I can get another one.

It has this on the capacitor:
Some obscure F in between two lines


Thanks, for this detailed answer. I hope this will help my brother with his Asus motherboard.

Lets try to get the capacitor specs from the markings:
Some obscure F in between two lines - that's the manufacturer's logo
89He - manufacturer's part code ?
101 - 10*10^1µF = 100µF (definitely µF not pF, elcos don't come in pF)
16 - 16V

So you need a 100µF 16V radial electrolyte capacitor. Make sure, you select a low ESR type. For the pin distance, measure the distance of the remaining old parts. Should be one or two tenth of an inch (100 / 200 mil, 2.54 / 5.08mm).

Where to buy? Where do you live? Mouser, RadioShack etc. As last resort look online.

Soldering the new one on the pins of the old one is not a good idea. Longer  connections mean more inductance and the design of the CPU power supply may be critical.

To remove the old pins, heat the pad from the bottom and pull slightly from the top with pincers, one pin at a time. The moment you removed the pin, push a very thin (0.5mm) graphite lead of a mechanical pencil into the hole. That will keep the hole open. Or use a solder sucking pump to suck the molten lead out of the hole.

If you put the new one in make sure, you get the polarity right. Normally, the negative side of the cap is marked, so the white half circle on the board seem to indicate the plus side (according to the caps still on the board). BTW: real good photos.

Thanks for the help guys. So would I run into any problems with the motherboard being multi-layered as mentioned by iceng? As it is multi-layered copper would I run into problems?

No. For double and multi layered the holes are not just holes in the PCB but have copper at the sides of the hole, connecting the various layers.

This copper tube will suck and hold the molten lead in. So when the thing cools the hole is closed with solid soldering lead.

That's why I mentioned the lead sucking pump resp. the graphite pencil lead trick to keep the hole open. It's more a nuisance than a problem.


5 years ago

I looks like the wire connections are easy to reach.

I can do surface mount, but on this multilayer PCB, I would hang a cap
to those wires, rather then risk damaging what cannot be seen.

BTW Good pictures, 


Agreed! Refreshing to see such well taken photographs in a question.

Thanks guys!

So far I have found 30 different codes for 50 different makers of electrolytic capacitors, depending on the maker the codes are different.

Most electrolytic capacitors are in uF but not all of them are.

Skipping alphanumerical codes.

These are codes for 100uF:

These are codes for 100 pF

Find the maker and check the code or guess, what’s the worst that can happen, you fry your motherboard.

Check major suppliers like Mouser. You don't need the exact brand. Just make sure you get the exact specs. If you can find the exact cap that came out that will help to verify what you need.